Potassium
Potassium is the major intracellular cation (sodium is major extracellular). 90% is exchangeable, with an inverse relationship to serum pH
Category Electrolytes
Calcium Metabolism
Calcium: highly regulated cation
involved in: cell death, duration and strength of cardiac muscle contraction, muscle contraction in blood vessels, airways and uterus, coagulation, bone metabolism, neurotransmitter and hormone release…
SIADH
Syndrome Of Inappropriate ADH secretion (SIADH) is hyponatraemia due to an increase in concentration of ADH inappropriate to the current osmotic or volume status. The differential diagnosis includes ADH analogues
Hyponatraemia
Hyponatraemia: common problem in ICU (30% of patients have a Na < 134mmol/L)
Hypokalaemia
Hypokalaemia: the most common electrolyte abnormality in hospitalised patients; mostly caused by drugs and GI disease
Hypocalcaemia
Hypocalcaemia: Reduced intake; redistribution and increased output
Hypernatraemia
Hypernatraemia can be caused by a number of critical illnesses: water depletion (decreased intake, hypotonic fluid loss – renal/non-renal); solute excess (Na+ or other)
Hyperkalaemia Management
Hyperkalaemia is a life-threatening emergency. Basic overview of hyperkalemia management
Hypercalcaemia
Ca2+ exists in the extracellular plasma two states: (1) free ionized state and (2) bound to other molecules (mostly albumin, rest – beta-globulins, phosphate, citrate)
ionized Ca2+ concentration is inversely related to pH -> an increase in pH results in a decrease in ionized Ca2+
Electrolyte Abnormalities Summary
Electrolyte Abnormalities Summary
Calcium Replacement
Calcium Replacement: controversial issue; generally accepted that patient should have replacement if ionised Ca2+ < 0.8mmol/L
Calcium basics
Calcium is the most abundant mineral in the body. 1.5% of body weight; 99% is in bone matrix; 1100gramm (27mmol)